A robot system and a robot controller, by which a teaching operation, etc., of a robot can be intuitively carried out by a simple operation. The robot has a sensor arranged on a surface of a movable part or the robot, and the sensor is configured to detect a three-dimensional position of an article, when the article contacts or is close to the sensor. When the article reaches a reference position, a mode change section switches a motion mode of the robot to a following mode. In the following mode, based on the direction of movement of the article from the reference position, the direction of motion of the robot is determined. Then, a motion control section controls the motion of each axis of the robot so that a portion where the article contacts moves in a direction generally the same as the direction of movement of the article.